THE STRUCTURAL AND BIOLOGICAL RELATIONSHIPS OF CEREAL PROTEINS INVOLVED IN TYPE I ALLERGY

摘要

Allergic reactions can occur following a variety of environmental challenges, including inhalation of dusts and particles such as pollen, and ingestion of foods. They generally involve generation of an IgE antibody response towards an environmental agent, known as an allergen. IgE binds to the surface of histamine containing masl cells which bind allergen, becoming cross-linked in the process. This triggers the release of mediators, such as histamine, from the mast cells, which proceed to cause the acute inflammatory reactions which are manifested in symptoms. These can include respiratory (asthma, rhinitis), cutaneous (eczema, urticaria) or gastrointestinal (vomiting, diarrhoea) symptoms which may occur alone or in combination. A rare but very severe reaction is anaphylactic shock characterised by respiratory symptoms, fainting, itching, urticaria, swelling of the throat or other mucous membranes, and a dramatic loss of blood pressure. Symptoms appear rapidly in allergic reactions, in contrast to food intolerances which are reproducible, some times non-immune-mediated, reactions whose symptoms can sometimes take days to manifest themselves, an example of which is the gluten intolerance syndrome, Coeliac's disease. This review is restricted to IgE-mediated allergies, which essentially develop in two phases -(1) sensitisalion and (2) subsequent reaction on re-exposure to an allergen. Both stages are triggered by allergens which are almost always proteins.